Any launcher can do the job. The *issue* is the method the OP wants to do it. He wants the first game to be completed before the player then goes into the second game. In order for the player to not be able to skip the 50th level or the first game and go right into the second would require some information to be passed from the first game to either the "button" to launch the second game or the second game itself.
If S4Real has a launcher to do that specific task then great. MrValentine is correct that DBP can also accomplish this. We use Visual Basic ourselves and create our launcher to hold multiple items (games, manuals, walkthroughs, videos, etc) since our time with VB is far more extensive than with DBP. The main point is that an external item will be needed, and depending on how you want the result to be, may require some additional work either to the launcher or FPSC source.
For example, we have a development we released that contained two game builds of 5 levels each. I built the launcher in VB and when run, two buttons appear- Game 1 and Game 2. The Game 2 button is greyed out because the launcher was told that Game 1 has not been completed. When the user gets to the end of Game 1, there is a code they are given. When they return to the launcher menu, they input the code and the second game is "unlocked". Another development we did eliminated the need for "entering a code" as I have my source writing the data to a file that the launcher reads and acts according.
There are many methods that can be deployed, but it may or may not be as easy as some might think, depending on how you want the sequence of events to go.
There's no problem that can't be solved without applying a little scripting.